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Gram positive and gram negative bacteria
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Recommended: Gram positive and gram negative bacteria
This lab experiment was conducted in order to identify and confirm the presence of three types of organism within an unknown broth culture. The organism that were being tested fall under the categories of gram-positive, gram-negative paracolons, and gram-negative coliform. Gram positive organism are known to have thick cell wall made up of peptidoglycan, which are cross-link sugar chains with peptide bonds (Carson 13). Gram-positive bacteria are found within the phylum Firmicuites (Slonczewski & Foster 94). While gram-negative, have thin layers of one or two peptidoglycan cell wall, this type of bacteria are found within the phylum Proteobacteria (Slonczewaki & Foster). The gram positive and negative characteristic derived from a staining technique that was developed by Hans …show more content…
Individual colonies are better to work with because the organism can be aseptically transferred to another media, to create a pure culture. This helps narrow down specifically the type of organism of interest (Carson 19). During the culturing process, there are a lot of information that can help deduce the type of organism that are cultured. Some of the characteristic that are used in the identification of cultured organism are known as colony morphology (Carson 20). Colony morphology take in consideration the following characteristic of the culture: Size (small, medium, large), pigment (coloration), optical properties (opaque, translucent, transparent), surface (shiny, smooth, and mucoid) form (circular, irregular, and rhizoid), margin (lobate, undulate, filamentous or serrate), and elevation (flat, raised, umbonate, or convex) (Carson 20). In a more microscopic level, cellular characteristic may apply to the individual cell within a colony, otherwise known as cellular morphology. The agar plate were used during this experiment have selective and differential properties that help to differentiate between organism. A selective media will actively select for or against a particular
Haemolytic colonies were classified by a white ring around the patched colony, indicating that haemolysis of the blood agar occurred. Conversely, non-haemolytic colonies were classified by a lack of a white ring, which indicated that no haemolysis took place.
After 48 hours of incubation the agar plates were viewed. Individual colonies were tested for successful isolation by gram staining and then viewing the stained bacteria under a microscope. Isolation was successful. One colony of each unknown bacteria was transferred to an agar slant for growth. The agar slants were stored at room temperature over the weekend so that they would not grow too much.
Streak plate technique was used to isolate pure culture for each bacteria (2). The Gram stain was used to determine Gram reaction and morphology of each bacteria (2) Selective and differential media such as, salt agar, MacConkey agar and blood agar were used for bacterial identification (2). Gelatin deeps were inoculated to detect production of gelatinase (2). Starch Agar plate were inoculated to detect amylase (2). Ocular reticle used to determine bacteria size (2). Motility deeps were inoculated to detect motility on bacteria (2). Thioglycollate broth used to determine oxygen requirements (2). Carbohydrate fermentation
Planarians are free-living, carnivorous flatworms found in the Phylum Platyhelminthes, Class Turbellaria. Although the Phylum Platyhelminthes is known for having the animals with the most parasitic species, the class Turbellaria which consist of the Planaria, are a non-parasitic species. Platyhelminthes which translates to "flat worm" are triploblastic animals. This means that they have three tissue layers, the endoderm, mesoderm, and ectoderm. Planaria also are monoecious organisms, meaning that they have both female and male sex organs in one organism. Another characteristic of the Planaria is that they do not have a true body cavity, meaning that they are acoelomate organisms.
The purpose of this study is to identify an unknown bacterium from a mixed culture, by conducting different biochemical tests. Bacteria are an integral part of our ecosystem. They can be found anywhere and identifying them becomes crucial to understanding their characteristics and their effects on other living things, especially humans. Biochemical testing helps us identify the microorganism present with great accuracy. The tests used in this experiment are rudimentary but are fundamental starting points for tests used in medical labs and helps students attain a better understanding of how tests are conducted in a real lab setting. The first step in this process is to use gram-staining technique to narrow down the unknown bacteria into one of the two big domains; gram-negative and gram-positive. Once the gram type is identified, biochemical tests are conducted to narrow down the specific bacterial species. These biochemical tests are process of elimination that relies on the bacteria’s ability to breakdown certain kinds of food sources, their respiratory abilities and other biochemical conditions found in nature.
The results of the gram stain test were cocci and purple. This indicated that the unknown bacteria were gram positive. The gram stain test eliminated Escherichia coli, Klebsiella pneumonia, Salmonella enterica, and Yersinia enterocolitica as choices because these bacteria are gram negative. Next a Blood Agar plate was used because in order to do a MSA or a Catalase test there needs to be a colony of the bacteria. The result of the Blood Agar plate was nonhemolytic.
The purpose of this laboratory is to learn about cultural, morphological, and biochemical characteristics that are used in identifying bacterial isolates. Besides identifying the unknown culture, students also gain an understanding of the process of identification and the techniques and theory behind the process. Experiments such as gram stain, negative stain, endospore and other important tests in identifying unknown bacteria are performed. Various chemical tests were done and the results were carefully determined to identify the unknown bacteria. First session of lab started of by the selection of an unknown bacterium then inoculations of 2 tryptic soy gar (TSA) slants, 1 nutrient broth (TSB), 1 nutrient gelatin deep, 1 motility
I was given unknown organism #14, in order to find out what organism I had, I had to perform several different biochemical tests to identify it. Starting with the Gram stain test, which is performed to differentiate Gram-positive and Gram-negative cells. After staining, when observed through the microscope Gram-positive cells are a purple color with thick peptidoglycan cell walls. Gram-negative cells are a pinkish/red color with thinner cell walls. (handout G. s.) My organism was observed to be pinkish rod shaped meaning it is Gram-negative bacteria.
In pursuit of national glory, profit and religious mission, England started to explore and conquer the North America. Through the 1600s and the early 1700s, three major colonial regions, the New England colonies, the Middle colonies, and the Southern colonies, formed and developed, and the economic freedom from land owning drew people to the North America. However, during and after the French-Indian War, colonies cooperated to resist British policies and finally declared their independence in 1776.
The purpose of this project was to identify unknown bacteria species from a mixed culture. The two unknown species were initially plated onto Tryptic Soy Agar (TSA), Eosin Methylene Blue (EMB), Mannitol Salt Agar (MSA), and blood agar plates to distinguish between the two different bacteria using colony size, color, shape, and growth characteristics. By identifying and inoculating the differing types of colonies, the two unknown bacteria were purified and able to be tested
In conclusion, the unknown microorganism which eighteen tests were performed on matches up with the microorganism Enterobacter aerogenes. The gram stain looks exactly like it is supposed to, gram-negative which makes it pink and the results for every test except the three experimental errors match up with this microorganism. The objective of performing various test on an unknown microorganism was to be able to correctly identify the unknown microorganism based on its’ characteristics and the results that follow, this objective was achieved because the microorganism turned out to be true by the results that were found from the tests. The unknown microorganism that was given at random was in fact Enterobacter aerogenes.
I identified the genus and species of an unknown bacterial culture, #16, and I applied the following knowledge of morphologic, cultural and metabolic characteristics of the unknown microorganism according to the laboratory manual as well as my class notes and power point print outs. I was given an incubated agar slant labeled #16 and a rack of different tests to either examine or perform myself; the tests are as follows: Gram Stain; Nutrient Gelatin Test; Carbohydrate Fermentation; Dextrose, Lactose and Sucrose; IMVIC tests; Citrate, Indole, Mythel-Red and Vogues Proskauer test; as well as a Urease and TSI Test. Materials and Methods/Results Upon receiving the Microorganism (M.O.) #16, I prepared a slide by cleaning and drying it. Then, using a bottle of water I placed a sterile drop of water on the slide and used an inoculating loop, flame sterilized, I took a small sample of the unknown growth in my agar slant and smeared it onto the slide in a dime sized circle and then heat fixed it for ten minutes.
The “Fast Plant” experiment is an observation of a plants growth over the span of twenty-eight days. The objective is to observe how plants grow and use their resources throughout the span of their life. In our lab we observed the Brassica rapa, a herbaceous plant in the mustard family which has a short cycle which makes it a perfect plant to observe in this experiment. Like other plants the Brassica rapa must use the resources in the environment to create energy to complete itʻs life cycle and reproduce. By observing the plant it is easy to see in what organ or function the plant is using itʻs energy and resources and if overtime the resources switch to other part of the plants. By conducting this experiment we are able to observe where and how plants allocate their resources throughout their life by harvesting plants at different points in their life.
The Campylobacter species observed in 1886 from Theodor Escherich in the colonic mucus of infants who had died of “cholera infantum,” but they could not be cultured. (Miliotis & Bier 2003) Mc Fadyean and Stockman in 1909 first isolated Campylobacter fetus from aborted sheep fetuses. (Miliotis & Bier 2003) After that observed that the Campylobacter which called (Vibrio fetusovid), caused septic abortion in cattle. (Miliotis & Bier 2003) This pathogen bacterium starts to create problems dysentery in the cattle.( Miliotis & Bier 2003) In 1957 the King examined people which have bloody diarrhea the reason for the disease is the Campylobacter species. (Miliotis & Bier 2003)The species of Campylobacter are Campylobacter jejuni, Campylobacter coli, Campylobacter lari and Campylobacter fetus. (Miliotis & Bier 2003) The campyloCbacter is Gram-negative thin; (Siegrist 2014) Gram-negative bacteria are bacteria that do not retain the crystal violet dye in the Gram stain protocol. (Miliotis & Bier 2003) Gram-negative bacteria will thus appear red or pink following a Gram stain procedure due to the effects of the counter stain. (Miliotis & Bier 2003) The shape has the Campylobacter is curved and motile rod like S or spiral. (Siegrist 2014) Finally the Campylobacter has single polar flagella at one or both ends and they exhibit a rapid darting motion (Siegrist 2014), like picture1.
The Cell, the fundamental structural unit of all living organisms. Some cells are complete organisms, such as the unicellular bacteria and protozoa, others, such as nerve, liver, and muscle cells, are specialized components of multicellular organisms. In another words, without cells we wouldn’t be able to live or function correctly. There are Animal Cells and Plant Cells. In Biology class the other day we studied the Animal Cell. We were split into groups of our own and we each picked a different animal cell slide to observe. My group chose the slide,'; Smeared Frog Blood ';.